問題詳情
19. When a carbonyl is part of a conjugated π-network, the C=O stretch:
(A) has a higher frequency than in a nonconjugated system.
(B) has a lower frequency than in a nonconjugated system.
(C) always occurs at 1710 cm-1.
(D) occurs around 2700 cm-1.
(E) cannot be distinguished from the C=O stretch in a nonconjugated system.
參考答案
答案：B
難度：非常困難0
統計：A(1),B(0),C(1),D(0),E(0)